Ethernet Everywhere

It’s been 31 years since Bob Metcalfe invented Ethernet protocol. With nearly 8 billion Ethernet ports, it could use be as ubiquitous as water and air, at least from Silicon Valley’s perspective. Today the networking technology thanks to its elegant simplicity has spread its tentacles everywhere from local area networks, homes, city networks and now is getting ready to take on the carrier networks. A special report.

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There are times even Bob Metcalfe, the father and inventor of Ethernet, gets surprised by the ever growing popularity of Ethernet networking protocol. What began, as a tiny experiment for him has become a dominant force inside of corporate networks, city-wide networks (also known as metro networks), inside consumer homes, and more recently in the new fangled wireless networks.

In 31 years, Ethernet has evolved from 1973 when 2.94 megabits per second was the top limit. Today 10 gigabit per second over Ethernet (also called 10 GigE) is fast becoming a norm. And now it is time for Ethernet’s final act – carrier networks which are going to adopt a grown-up version of the networking protocol in coming years.

Nan Chen, President of the Metro Ethernet Forum, the body pushing the standard says, “Our focus on the metropolitan network has been so successful that people no longer think in terms of Ethernet’s limitations, instead they ask us what will it do next? Now Carrier Ethernet is our answer.” Chen whose day job is pushing Ethernet edge devices for Atrica, one of the surprise survivors of telecom meltdown, sums it up when he says the game is to make carrier Ethernet have quality of service of ATM, reliability of SONET and ease of use /Simplicity of Ethernet. Tall order but something that is sorely needed.

I got a chance to chat with Bob last week, and he said that it is time to stick a fork in SONET and other old school telecom networking technologies, that were more suited to the voice networks of the yore than modern broadband networks. “Its time that we start seeing the Internet infrastructure move over to a new technology because of all these new applications,” says Metcalfe.

“I see Ethernet developing in four directions: UP, DOWN, OVER and ACROSS. UP in speed – whether we jump to 40Gbps or 100Gbps … DOWN to the 8 billion processors shipped each .. OVER wireless links – WiFi, WiMax, ZigBee … ACROSS the telechasm between LANs and WAN.”

Service providers in Asia Pacific and Europe are turning to Ethernet, says Metcalfe. You see newer economies like India and China openly embracing the Ethernet bandwidth gusher. Cisco, for example has sold lot of gear to Tata Indicom Broadband Services, which is going to sell 10-to-100 megabits per second service to businesses in Bombay. Consumers are going to get the same Ethernet service for about $40 a month. Nearly a million customers are going to eventually connect to this network. Eight cities in total will eventually go online over Ethernet. Reliance is also building similar networks and are a big customer of Atrica, incidentally. In US, Cox and SBC are two of the incumbents who have expressed their pleasure with carrier Ethernet.
Infonetics Research forecasts that the total the carrier Ethernet sales will jump from a puny $61 million in 2004, or 2 percent of total metro Ethernet sales to $2.7 billion, or 35 percent of metro Ethernet sales, in 2008. The key driver of the sales many feel is going to be convergence and rollout of IPTV in many parts of the world including United States, says Rick Thompson, analyst with research firm, Heavy Reading. He points out companies like Force 10 Networks and Foundry Networks are seeing a sharp increased in demand from ISPs and carriers for their 10G switches, because they are trying to circle their IP core routers with these switches, which are cheaper and easier to manage.

“Core IP networks and routers have been shrouded in lot of mystery and magic,” says Thompson. “Ethernet is relatively simple and as a result you can have a simpler network. Ethernet… that’s an interesting trend.” Metcalfe couldn’t have said it better.

Most LAN centric people have gotten away with bashing SONET because of lack of knowledge on their part and the audience (who is much more familiar with LAN networks). In many cases SONET remains a very low cost solution. That said the Ethernet frame wrapped into a lot of RFCs and some MEF tweaks will eventually become the norm. But this is very different that CSMA/CD shared ethernet.

Its better to think “IP Networking has won” and IP doesn’t care what the physical layer is. Thus the lowest cost Layer 2 is the preferred choice because most features happen at Layer 3 and up.

The original Ethernet has two components – MAC protocol CSMA/CD and the frame format. What made Ethernet ubiquitous is CSMA/CD. But all these modern incarnations do not use CSMA/CD. How could they when they are optical systems?

Am I right in my thinking? Metcalfe is faulting SONET because it has 125usec framing structure?